Centrifuge



June 14, 1960 c. E. APPLEGATE 2,940,662

. CENTRIFUGE Filed Dec. 23, 1957 United States Patent CENTRIFUGE Charles E. Applegate, Weston, Mass., assignor, by mesne assignments, to Protein Foundation Incorporated, a corporation of Massachusetts Filed Dec. 23, 1957,,S er. No. 704,497

'5 Claims. (Cl. 233-28) This invention relates to centrifugation and, more particularly, to centrifugal apparatus useful in the separation of the various components of animal blood, though it may equally well be used in the separation of components, having different specific gravities, of other liquids, fluids, suspensions, or the like.

In US. patent applications Serial Nos. 500,738 and now Patent No. 2,906,450; 500,746 and now Patent No. 2,906,452; 500,753 and now Patent No. 2,906,453; 500,- 787 and now abandoned; and 500,882 and now Patent No. 2,906,451, filed April 12, 1955, are described centrifugal apparatus and bowl structures therefor especially useful for carrying out various separations of the elements of whole blood, that is, red blood cells, white blood cells, platelets and plasma which differ in specific gravity. 7

The present invention is directed to improved centrifuge bowl structures especially adapted for use with the centrifugal apparatus described in said applications, such improved bowl structures providing continuous separation of two components of differing specific gravity, with collection in the centrifuge bowl of one or more additional components as desired.

It is a particular feature of the invention that, with two component separation, true continuous separation, not limited as to either component by bowl volume, is achieved. Thus, the quantity of liquid to be separated into two components is independent of bowl volume so that a uniformly small bowl may be used for any quantity of liquid to be separated.

it is another feature of the invention that a third component of specific gravity intermediate between the two components to be continuously separated is collected in the bowl during such continuous separation and may be periodically discharged therefrom.

It is still another featured the invention that a component of specific gravity intermediate between said two components may be subiected to unusually high forces for better separation thereof from the lightest component to be separated, so that, for example, a fourth component of specific gravity intermediate between said third component and the lightest of said two. components may be so separated and collected.

It is an important feature of the invention that any of the above mentioned separations may be carried out under sterile conditions as is especially important with fluids of animal origin, such as whole blood.

Various other objects and features of the invention will become apparent from the following description of preferred embodiments thereof, together with the accompanying drawings wherein Fig. 1 is a cross-sectional view showing the centrifuge bowl structure of the present invention;

.Fig. 2 isa diagrammatic cross-sectional view showing the operation of the bowl of Fig. 1 during continuous separation of two components and collection in said bowl of a third component;

Fig.3 is a diagrammatic cross-sectional view showing the operation of the bowl of Fig. 1 during discharge of said third component;

Fig. '4 is a partial cross-sectional view showing a modificationof the bowl of Fig. 1; and

Fig. 5 is adiagrammatic cross-sectional view showing the operation of the bowl of Fig. 2 during continuous separation of two components and collection in said bowl of a third and a fourth component. I

The centrifuge bowl structures of the present invention are adapted to be used with the centrifugal apparatus as shown in said applications Serial Nos. 500,738; 500,746; 500,753; 500,787 and 500,882, and hence such apparatus will not be described herein in detail. Briefly, however, the apparatus supports and drives the centrifuge bowl and holds the external collecting receptacles, the bowl being rotatably mounted on a base which includes a table portion 6 and a cylindrical portion 8 removably mounted therein for directly supporting the lower portions of the bowl. The bowl is driven by a magnetic chuck (not shown) adapted to contact the bowl in the upper portion thereof.

The centrifuge bowl itself in general includes a top bowl 10 of generally conical shape having a top wall and an outwardly and downwardly sloping side wall, a bottom bowl 12 also of conical shape, and a compression arrangement including outer compressor ring 14 holding the two bowls together. The bowls and other elements which come in contact with blood are preferably of stainless steel with a silicone coating.

With a multiple piece centrifuge bowl as herein described, it is important that a fluid-tight seal be provided between the top and bottom centrifuge bowls and the intermediate ring. Thus, the top bowl has an outwardly extending annular flange 11 at its lower edge and the bottom bowl 12 has a similar flange 13 at its upper edge. The peripheral rim portion of the internal elements 40 and 4-4, as hereinafter described, is interposed between the flanges, and suitable sealing means comprising 0 rings 16 are interposed as required, between 'said rim portions and flanges 1.1, 13 respectively. Spacing rings 17 are also interposed between said rimportions and flanges 11, 13 radially inwardly of the 0 rings to limit the movement of flanges 11, 13 toward one another, said spacing rings being of a dimension somewhat less than that of the uncompressed 0 rings. Thus, a predetermined overall dimension of the assembled centrifuge can be provided, yet with adequate sealing. The opposed flanges 11, 13 are urged together by outer compression ring 14 and inner compression ring 15, the outer compression ring having an inwardly extending flange which fits over top bowl flange 11. The downwardly extending skirt of the compression ring itself is screw threaded on its inner surface to cooperate with the screw threaded outer surface of its cooperating locking ring 15, the upper surface of said latter ring contacting the bottom bowl flange as it is screwed into place to clamp flanges 11, 13 together.

Figs. 1 and 4 show the centrifuge bowl structure above described with various interior bafile arrangements according to the present invention, and Figs. 2, 3 and 5 show the operation of said bowl structures with the bowl running for the separation of the blood components. It will be noted that the outside of the bowl is the same in each case as with the bowl of said applications and only its interior structure has been changed in accordance with the present invention to provide continuous separation of two components with collection of additional components within the bowl if so. desired.

As to the bowl structure shown in Fig. -1, the parts of the bowl are assembled on a cylindrical flanged base member 8, adapted to fit into an opening in table 6., The upper surface of the flange of said base 8 acts as a Patented June 14, 1960 running surface for a sealing member 27 of low-friction material, said memberbeing supported'betweensaid fiange and bottom bowl 12 by a skirt 28 thereon. A waved spring washer 29. is provided interposed between said bowl and sai'd'fiange which controls thepressure therebet-ween henicl-am i ring 15 is .ttg tt he h e the bow'l'isprop'erly assembled).' A su-itable".G'ringseal is provided between memberi27 andf's'kirt 28.

'f The" base 8 has Qinounted centrally thereof an upstand ing stationary feed tube housing 30, 'said} housing having sion. spring .34 interposed between said feedtubeand said" base to normally urge said ffee'dtube upwardly. The feed.

tinuously separate red blood .cells R and plasmaP is slidablymounted'therein a fe'cdtube32 with a compres diagrammatically shownin Fig. 2. Thus, with the centrifuge spinningywho'le blood or other liquid having at least 'two'components isfed upwardly through feed tube 32 and passes radiallyioutwardly to theiouter side wallof upper bowl 10. The heaviercomponent, the red blood cells R, fills the compartment formed by said wall and tube extends downwardly through 'base 8't'o a suitable. I

: connector so that blood from a donor orothenreservoir maylbeffedto thetcentrifuge. A pair of upstanding cylm-' dr'ical members .20 and 22 are provided on the base, the

outer of said members'20 being spacedbetween the inner and outer radial extent of the base aud'the inner of said members 22 being positioned between the outer member and housing 30. A plurality of openings are provided in said base in addition to said central opening for carrying away liquids discharged from the centrifuge to suitable glass or plastic containers, for example. Thus an outer opening having a downwardly extending tube 21 is provided in base 8 between its members 2!} and 22 and an inner opening 23 is provided in. base 8 between inner member 22 and feed tube housing 30, and an opening having a vent tube 25 is provided in said base outwardly of member Ztl'wi-thin lower'bowl .12. i

In Fig. lis shown a centrifuge bowl structure having" 7 internal centrifugeelements providing a baflde assembly especiallyfadapted for the continuous separation of two liquid components without collection of either in the V bowl, but with the collection in saidbowl of a third component having a specific gravity between said two compouents, as willoccur in the continuous separation of whole :blood into red cells R and plasma P, with collec- "An upper annular element is mounted adjacent theflanges 11, 13 above the .rim of lower element 46. andin contact therewith. Thespace 46 between the elements, thus extendsradially-outwardly from edge 4l -but termi natcsshort of the outer edge of said elements; communication'betweenthe outer end'of space 46 and the interior of top bowl 10 beingprovided by an outer series of bores therethrough adjacent the outer edge of said bowl. The inner edge of the upper annular element 44 exthe annular wall formed by .element*40 and'then begins to flow over inner edge 41"aud -o'uter llan'ge 42 downwardly into tube 21. The lighter liquid collects above upper element 44 and then begins to flow downwardly through openings 47 over inner flange 49 into tube 23 so 'that both are continuously separated and collected outside of the bowl in suitable containers, and with true two component mixtures, this separation may be continued indefinitely. With whole blood, however, there exists an intermediate specificgravity portion which for simplicity may be denoted the white cells W, such white cells, during the continuous separation of the red blood cells and plasma, being collected in the bowl above element 44 between the layers of red blood cells and plasma. When its quantity builds up so that it begins to pass through openings .47 with the plasma 'P, infeed of whole bloodthrough central openiug 32 is timed and the speed of rotation of the bowl gradually slowed. This provides a condition as shown in Fig; 3 wherein theaccumulated white base 8, sothat liquid dischargedtherefrom will pass into outertube 21."

lowersaid element 49 spaced therefrom inwardly'of its outer contacting rim, said rim being positioned between tween, the white cells and the plasma.

tendssubstantiallyinwardly beyond the inner edge 41 of lower'element 4d and is provided with a cylindrical flange which'extendsupwardly'therefrom and with a cylindrical flange 49 whichextendsidownwardly'there from. Said" lower flange-49 is spaced radially outwardly of upper' flan gefi s' andin a position within the inner sta- ,tionaty cylindrical member or collecting ring 22 on base 8 outside pffhousing 39." Communication through elecells W pass outwardly through outlet 23 and may be separately collected by suitable valve means as the speed continues to be'gradually decreased. After a suitable portion of the accumulated white cells W have been so removed, the bowl is speeded up so that its normal operation, continuously to separate red cells and plasma, can be resumed, the boundary between the white cells and plasma then becoming nearly vertical again butspaced well outwardly of openings 47; Similarly, intermediate components of other three component liquids and the like may be periodicallyremoved when they accumulate sufiiciently to interfere with the continuous separation of the othertwo components.

1 The-structure of Fig. 4 is in effect a structure modi- 'fied from the structure of Fig. 1 above described to'inelude an annular recess above theupper element 44to separate an intermediate specific gravity liquid by appli cation of high forces and to collect it in such recess. This situation occurs inthe separation of platelets from plasma, such being intermediate in specific gravity bestruction standpoint, an'additional'imperforate annular portion Si is spaced above the upper element 44, withgan imperforatecylindrical wall 52 extending. therebetween downwardly from the outerfedge thereof, the inner edge of said portion '59 preferably being positioned at least not substantially outwardly with respect. to the inner edge .1 of lower annular portion 40; l

,The operation of the structure of Fig. '4 is shown in Fig. 5 and is generally similarto the operation described above with reference toPig. l exceptxthat the plasma,- the lightest component, before passing through openings 47., its the recess formed by walls '50, 52 and 44. Since theend wall 52 of such recess is positioned substantially outwardly of openings 47,'the high force there provided results in improved separation oftheplasma P front-high- 'er specific gravity but difiicult to separate.'material,most:

ly platelets L, so that a' platelet free plasma may be continuously"separated, with platelets 'L being :collectedin the recess, and with the white cells W being collected above wall 5!} much as before; i i With either of the ,above described structures, upon Thus, frorna constopping of rotation, all of the material remaining therein will drain by gravity so that, if desired, any accumulated intermediate specific gravity materials can be removed without disassembly, as can the remainder of the two materials undergoing continuous separation.

Thus, it is apparent that the invention has provided a novel apparatus for separating components from blood during the actual phlebotomy, which apparatus results in improved separation, closed-system sterility and ease of operation with continuous separation of two components, without collection of either in the bowl, and with the separation and collection of further components if desired. Various modifications of the apparatus, not herein disclosed, within the spirit of the invention and the scope of the appended claims will occur to those skilled in the art.

I claim:

1. A centrifuge comprising a closed top bowl having an outwardly and downwardly sloping side wall, an internal centrifuge element having a central baflle structure including a lower imperforate annular portion extending inwardly from the circumferential wall of said bowl and terminating at its inner edge in a circular central opening and an upper imperforate annular portion spaced thereabove extending outwardly beyond said inner edge of said lower portion and substantially inwardly therebeyond with its outer imperforate edge defined by an annular series of bores, said annular portions having inner cylindrical flanges extending downwardly from each of inner edges of said annular portions with the upper flange positioned inwardly from the lower flange, a startionary base positioned beneath said bowl and said element, stationary feed means extending upwardly from said base centrally through said element for feeding liquid into said centrifuge at a point adjacent the top wall of said bowl, and means disposed below said central opening for collecting liquids discharged from the inner edges of each of said upper and lower annular baflie portions to said centrifuge including an upstanding cylindrical member positioned radially outwardly from said inner flange and radially inwardly from said outer flange, said centrifuge being adapted for rotation whereby two liquids of differing specific gravity are continuously discharged from said centrifuge during spinning thereof said internal centrifuge element including an imperforate annular portion spaced above said upper annular portion and having a cylindrical wall extending therebetween outwardly from the inner edge thereof forming an annular recess for collecting a liquid having a specific gravity intermediate said two liquids.

2. A centrifuge as claimed in claim 1 wherein said annular portion spaced above said upper annular portion has its inner edge positioned at least not outwardly with respect to the inner edge of said upper annular portion.

3. A centrifuge comprising a bottom bowl having a central opening therein, a side wall, and an outwardly extending annular flange at the upper edge of said wall, a stationary base positioned beneath said central opening, sealing means interposed between said base and said bottom bowl, a top bowl having a top wall, an outwardly and downwardly flaring conical side wall and an outwardly extending annular flange at the lower edge of said wall, a central baflie assembly of generally circular shape comprising a lower fiat circular plate with its outer imperforate annular edge positioned between said opposed flanges and having a central opening with an inner annular imperforate edge and an upper flat circular plate spaced a limited distance upwardly from said lower flat circular plate to form a. passageway therebetween and having a central opening with an inner annular imperforate edge with the outer imperforate annular edge of said upper flat circular plate extending to a point adjacent to but spaced inwardly from the inner surface of said top bowl and defined by an annular series of bores providing a passageway from the outer annular imperiorate edge of said upper plate to the inner annular imperforate edge of said lower plate, the inner imperferate annular edge of said lower plate being positioned radially outwardly of the inner imperforate annular edge of said upper plate, and stationary feed means extending upwardly from said base centrally through the central openings of said plates for feeding liquid into said centrifuge at a point adjacent the top wall of said bowl, said centrifuge being adapted for rotation whereby two liquids of differing specific gravity are separately and continuously discharged respectively from the inner annular edge of the lower plate and the inner annular edge of the upper plate.

4. A centrifuge as claimed in claim 3 wherein said central bafile assembly further comprises an upwardly extending tubular skirt on said upper plate and an inwardly extending annular plate having its outer edge mounted on said upwardly extending skirt and a central opening, said upwardly extending tubular skirt and said inwardly extending annular plate providing an annular recess for collecting a liquid having a specific gravity intermediate said two liquids.

5. A centrifuge comprising a bottom bowl having a central opening therein, a side wall, and an outwardly extending annular flange at the upper edge of said wall, a stationary base positioned beneath said central opening, sealing means interposed between said base and said bottom bowl, a top bowl having a top wall, an outwardly and downwardly flaring conical side walls and outwardly extending annular flange at the lower edge of said wall, a central baffle assembly of generally circular shape comprising a lower flat circular plate with its outer imperforate aimular edge positioned between said opposed flanges and having a central opening with an inner annular imperforate edge and a downwardly extending tubular skirt positioned outwardly of said inner annular edge of said lower plate and an upper flat circular plate spaced a limited distance upwardly from said lower flat circular plate to form a passageway therebetween said upper plate having a central opening with an inner annular imperforate edge and a tubular skirt positioned outwardly thereof with the outer imperforate annular edge of said upper flat circular plate extending to a point adjacent to but spaced inwardly from the inner surface of said top bowl and defined by an annular series of bores providing a passageway from the outer annular imperforate edge of said upper plate to the inner annular imperforate edge of said lower plate, the inner imperferate annular edge of said lower plate being positioned radially outwardly of the tubular skirt of said upper plate, stationary feed means extending upwardly from said base centrally through the central openings of said plates for feeding liquid into said centrifuge at a point adjacent the top wall of said bowl, and collecting means on said base including a collecting ring extending upwardly between said downwardly extending tubular skirts, said centrifuge being adapted for rotation whereby two liquids of differing specific gravity are separately and continuously discharged respectively from the inner annular edge of the lower plate and the inner annular edge of the upper plate.

References Cited in the file of this patent UNITED STATES PATENTS 1,373,743 Jones Apr. 5, 1921 2,678,159 Ellis May 11, 1954 2,822,126 Cohn Feb. 4, 1958 

